Hi, I disagree with Hiro's conclusion that we should not take data for the 22 GeV run. Even if we end up not being able to achieve a reliable multiplicity, I'm not convinced that we couldn't obtain a useful distribution for central events. I also think it is bad politics to not at least try to make something of available beam. ..steve Hironori Ito wrote: > For 22 Gev run, I am not sure it is possible to get multiplicity >results because ZDC is only about 10 % efficient with this energy. This >means we (or I ) are not sure what fraction of the total cross section is >measured for those energy. (I do not know what PHOBOS is thinking. Also, >I need more statistics than what PHOBOS needs because our detector cover >smaller solid angle than they do.) Any ideas are welcome, but otherwise I >think it is a waist of shifters' time. > > hiro > >On Sat, 17 Nov 2001, [iso-8859-1] Jens Jørgen Gaardhøje wrote: > >>Hello friends >>As concerns the run. >>-Ian and I discussed the 12 deg statistics yesterday based on a fisrt analyis of a run at the present setting. >>It is still to early to really evaluate the present run, but it seems likely that we will not have time to do 2 polarities at this >>angle and high field setting. We will need to make a final decision by monady or tuesday. >>-I would think that we should run at 22 GeV. If nothing else we should be able to get the multiplicity distributions. >>regards >>JJ >> >>________________________________ >>Jens Jørgen Gaardhøje >>Assoc. prof. Dr. Scient. >>Chair Ph.D: school of Physics NBI.f.AFG. >>(secretariat. 35 32 04 41) >>Chair science committee. UNESCO Natl. Commission. >>(secretariat. 33 92 52 16) >>Office: Niels Bohr Institute, Blegdamsvej 17, >>2100, Copenhagen, Denmark. >>Tlf: (+45) 35 32 53 09 >>Fax: (+45) 35 32 50 16 >>________________________________ >> ----- Original Message ----- >> From: Flemming Videbaek >> To: brahms-l@bnl.gov >> Sent: Saturday, November 17, 2001 5:10 PM >> Subject: run status >> >> >> >> The AuAu running is going into the last 8 days of running. The machine has run fairly well in recent eve+nights and this is expected >> to continue over the weekend. The yellow beam still has lifetime problems, and and 12 hour beam development period is scheduled from >> Monday morning 6.00 am. >> >> - Please turn magnets to 0 field, and standby at that time. >> >> - The running at 12 deg 2/3 fields has started (.66 M) collected >> aim up to 810M at 2/3 field (and at least 4M) >> - 40 deg 1.5 M for HBT is complete. >> - The high statistics program at 90 deg has started - there is an issue if the retracted position (i.e. reduced solid angle by 25%) is >> an issue. >> >> In the previous e-mail I requested, and will like to repeat a call for un-finished business. e.g angles, fields in the exsisting program >> that needs repeating, or special runs that enhanches our understanding of present data or in preparation for upcoming runs. >> >> So far there are a couple of items >> >> - Michael M. requested a short run ~100K minbias data with reduced ZDC HV to understand tube saturation. >> - I will like to take a several hours to develop the H1/H2 trigger setup, probably middle of the week (though not Thursday) >> - Michael suggested we study the 22GeV beam, not so much to take physics data, but to gain insight how to deal >> with lower energy beams in preparation for the future. E.g. ZDC threshold/settings/response triggering. He is planning to come to BNL >> for the weekend for this purpose. >> >> >> >>
This archive was generated by hypermail 2b30 : Sat Nov 17 2001 - 15:46:39 EST